from trex_stl_lib.api import *


class STLS1:
    def create_stream(self):
        base_pkt = Ether() / IP(src="2.2.0.1") / UDP(sport=12)

        pad = Padding()
        if len(base_pkt) < 64:
            pad_len = 64 - len(base_pkt)
            pad.load = "\x00" * pad_len

        vm = STLVM()

        vm.tuple_var(
            name="tuple",
            ip_min="173.16.1.3",
            ip_max="173.16.40.18",
            port_min=1025,
            port_max=1124,
            limit_flows=1000000,
        )

        vm.write(fv_name="tuple.ip", pkt_offset="IP.dst")
        vm.fix_chksum()

        vm.write(fv_name="tuple.port", pkt_offset="UDP.dport")

        pkt = STLPktBuilder(pkt=base_pkt / pad, vm=vm)

        return STLStream(packet=pkt, mode=STLTXCont())

    def get_streams(self, direction=0, **kwargs):
        return [self.create_stream()]


# dynamic load - used for trex console or simulator
def register():
    return STLS1()
